Leaves of physaria ludoviciana
are narrow and relatively long, either linear, or slightly wider above or below the middle. Leaf edges may have a few shallow teeth but are usually entire. Leaves are often slightly folded up along the axis. Stem leaves are only a little shorter than basal leaves; up to 2 inches. Stems and leaves are evenly covered by short, branched hairs (four to seven rays, and the rays themselves are divided). Stems are often purplish towards the base. Plants produce several stems, from the base, some pointing directly upwards, others decumbent.
Flower clusters are compact, becoming elongated when fruiting begins. The four narrow, greenish sepals are oblong, and the two opposite pairs are slightly different in shape, while the four yellow petals are obovate, and slightly longer; around a third of an inch. At the center are one style and six yellow stamens, not exserted. Fruits are green, oval-shaped pods, a quarter of an inch long.